Evaluation of Serum Cystatin C as a Marker of Early Renal Impairment in Patients with Liver Cirrhosis

Abstract

Background. Serum cystatin C (CysC) was proposed as an effective reflection of the glomerular filtration rate (GFR). However, its role in patients with liver cirrhosis has not been extensively verified especially in the detection of early RI. Patients and Methods. Seventy consecutive potential candidates for living donor liver transplantation with serum creatinine (Cr) <1.5 mg/dL were included. CysC, Cr, and estimated GFR [creatinine clearance (CCr), Cockcroft-Gault formula (C-G), MDRD equations with 4 and 6 variables, CKD-EPI-Cr, CKD-EPI-CysC, and CKD-EPI-Cr-CysC] were all correlated to isotopic GFR. Early RI was defined as GFR of 60–89 mL/min/1.73 m2. Results. Patients were 25.7% and 74.3% Child-Pugh classes B and C, respectively. GFR was ≥90, 60–89, and 30–59 mL/min/1.73 m2 in 31.4%, 64.3%, and 4.3% of the patients, respectively. All markers and equations, except C-G, were significantly correlated to GFR with CKD-EPI-Cr-CysC formula having the highest correlation (r = 0.474) and the largest area under the ROC curve (0.808) for discriminating early RI. At a cutoff value of 1.2 mg/L, CysC was 89.6% sensitive and 63.6% specific in detecting early RI. Conclusion. In patients with liver cirrhosis, CysC and CysC-based equations showed the highest significant correlation to GFR and were measures that best discriminated early RI.

Comparison of Performance of Improved Serum Estimators of Glomerular Filtration Rate (GFR) to 99mTc-DTPA GFR Methods in Patients with Hepatic Cirrhosis

“…Another study (12) used a camera-based 99m Tc-DTPA method for measuring GFR. Although the camera-based method can be useful in following patients over time, we and others have shown that this method correlates poorly with more traditional reference methods for measuring GFR (12). An additional study used urinary excretion of 99m Tc-DTPA but did not include details regarding methods to ensure complete urine collections (11).…”

“…In a limited number of studies in patients with cirrhosis, the CysC equations tend to show better results than methods based solely on SCr. However, the published performance of the equations is variable, creating uncertainty as to whether these equations may obviate the need for more accurate methods for measuring GFR in cirrhotics (11)(12)(13)(14)(15).…”

“…Several publications have addressed the value of improved prediction equations for estimating GFR in patients with hepatic cirrhosis (11)(12)(13)(14)(15)20). However, these reports have compared the performance of the eGFR equations with very disparate reference methods for measured GFR (mGFR).…”

Plasma cystatin C is a predictor of renal dysfunction, acute‐on‐chronic liver failure, and mortality in patients with acutely decompensated liver cirrhosis

“…For example, De Souza et al evaluated over 200 patients awaiting liver transplantation and found that CysC‐based equations more precisely determined the GFR than Crea‐based equations . This was confirmed in various groups of patients with liver cirrhosis . Furthermore, previous small studies suggested CysC as a predictor for HRS and mortality .…”

“…(23) This was confirmed in various groups of patients with liver cirrhosis. (24,25) Furthermore, previous small studies suggested CysC as a predictor for HRS and mortality. (26,27) In a small cohort of 49 patients, CysC-based estimations of GFR were predictive for overall survival.…”